Interspecific hybridization to breed the abiotic stress tolerance in Lotus genus. Effect of combined salinity and waterlogging stress

ANTONELLI C.J.; ESCARAY F.J.; CAMPESTRE M.P.; BABUIN M.F.; CALZADILLA P.I.; RUIZ O.A.

CABA

Simposio; 5th International Symposium of Forage Breeding (ISFB 2015); 2015

Waterlogging is an important abiotic stress whichoften occurs in Flooding Pampa Grassland in Argentina and affects foragerspecies, particularly legumes. The combination between waterlogging andsalinity intensifies plant stress and only few forage legumes are able topersist under these conditions. Some species of Lotus genus are capable of producing forage under marginal conditions;nevertheless the tolerance to the mentioned stress could be improved. For thispurpose our group studied four Lotusaccessions: L. tenuis (Lt), tetraploid L. corniculatus (LcT),diploid L. corniculatus (LcD) and hybrid material L. tenuis x L. corniculatus (LtxLcD). Plants were grown in a chamberwith controlled conditions and irrigated with Hoagland 0.5X solution. Treatmentsimposed during 3 weeks were: saline (NaCl-150,150 mM NaCl was added to Hoagland), waterlogging (WL, undrained Hoagland solution with reduced levels of O2),saline waterlogging (NaCl-WL) andcontrol (Ctrl). Productions ofbiomass, photosynthesis, efficiency of PSII and ion accumulation in differentplant tissues were evaluated. NaCl-WL and NaCl-150 treatments reduced the shootweight of Lt, LcT and LtxLcD; only LcD did not differ from control treatmentpresumably due to its lower growth rate. Similar results were obtained for netphotosynthesis. Efficiency of PSII was affected only in LcT under NaCl-WL. Inaddition, in this condition and for this accession, the highest levels of Na+and Cl- were recorded. Interestingly the LtxLcD accession showed thebest performance under NaCl-WL treatment, demonstrating that interspecifichybridization is an invaluable tool for improving tolerance in legume foragers.